JPS63262227A - Correcting method of laminate plate - Google Patents

Abstract

PURPOSE:To enable the laminate with twist, etc., to be continuously corrected accurately by passing the laminate between correcting rolls, while the laminate is heated at the temperature equal to the softening temperature of the main material or higher. CONSTITUTION:A laminate A-1 is heated in a furnace at the temperature equal to the softening temperature of the main material, and is passed between correcting rolls 4, thereby curing the laminate while cooling, with deformation being corrected. As the laminate, there are paper phenol laminate generally recognized to be organic insulation material, a paper epoxy laminate, a glass epoxy laminate, tetron epoxy laminate, etc. Heating at the temperature equal to the softening temperature of the main material or higher means the heating at the temperature equal to the softening temperature of high molecular weight resin or higher in the case of organic insulation material. The correcting rolls 4 are composed of a plurality of roll-pairs being opposite in parallel at a prescribed distance. Transferring temperature is determined by the means and condition of heating and cooling. If the condition of heating and cooling is arranged, it is sufficient.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for correcting deformations such as warping and twisting of a laminated board used for printed wiring boards, insulating boards, etc.

[Prior Art] Laminated boards made by bonding and laminating base materials such as paper, composites, and glass cloth with phenolic, epoxy, and polyimide resins can be used to create printed circuit boards by pasting copper foil, for example. It is used as. If such a laminated board has warpage, twists, twists, etc., various problems occur. In other words, when manufacturing printed wiring boards using laminates, most of the process is automated, so if the amount of deformation due to warping or twisting of the laminate exceeds the tolerance of the automatic machine, automatic manufacturing will no longer be possible. Usually, a working size of 2.0 mm or less is required. Furthermore, if there is a curvature or twist when applying the resist using the screen printing method, the ink may bleed and cause defective products. When mounting components on a printed wiring board, if the amount of deformation due to warpage or twisting exceeds the machine's allowable tolerances, automatic mounting will not be possible. In this case, a working size of 1.2 mm or less is required.

Regarding the warping and twisting mentioned above, please refer to JISC6484.
, C6485, etc. are referred to.

Therefore, the reverse deflection method and the heating and pressing method are conventionally known as methods for straightening laminated plates.

The reverse deflection method is a method in which a material that is warped in one direction is warped in the opposite direction to eliminate the warp.This method also includes a method in which the material is heated in advance. The heating and pressing method is a method in which a warped or twisted material is placed between two flat plates and heated and pressed to straighten the material.

[Problems to be Solved by the Invention] The conventional reverse deflection method described above has little effect on torsion, and the direction in which the laminate is introduced into the straightening machine is limited. That is, if the laminate is loaded in the opposite direction, the warpage will increase. It is necessary to adjust the size of the reverse warp depending on the size of the warp.
It is inconvenient to operate.

Since the heating h-mouth pressure method is basically a batch method, productivity is poor. Furthermore, it is not suitable for straightening laminates that adhere to each other, such as laminates with adhesive.

The present invention is a continuous straightening method that solves these conventional problems and can be performed with relatively simple operations.

[Means for Solving the Problems] The present invention involves heating a laminate to a temperature higher than the temperature at which its main material softens, and then cooling and hardening it while correcting deformation by passing it between straightening rolls. This is a method for straightening a laminate.

Examples of laminates applicable to the present invention include paper phenol laminates, which are generally referred to as organic insulators, paper epoxy laminates, glass epoxy laminates, composite laminates, glass polyimide laminates, glass polyester laminates, and Tetron. Examples include epoxy laminates. These may have copper foil or adhesive attached to their surfaces.

In the case of the above-mentioned organic insulator, heating to a temperature higher than the temperature at which the main material softens means that the temperature is higher than the temperature at which the polymer resin, which is the main material, softens.

In this case, the glass transition point of the polymer resin is the standard. In other words, if some molecules undergo glass transition due to heating, they will begin to soften to some extent, which will be effective in straightening. If the temperature is above the glass transition point, it will definitely soften and be effective.

The upper limit of the heating temperature is the temperature at which the material is softened to the extent that handling is not affected. This is the temperature at which the rigidity is maintained to the extent that it can be transported by roll.

The straightening roll is composed of a plurality of pairs of rolls facing each other in parallel with a predetermined interval. The diameter of each roll is determined by the pitch of the rolls. In order to reduce the pitch, the roll diameter must be reduced. Practically speaking, any diameter is sufficient as long as it has mechanical strength that does not cause more deflection than is allowed. It is better for the roll pitch to be as close to zero as possible. The upper limit is determined by the target warpage and twist rate. When the warpage and twisting rate is 1% as the target, the plate to be straightened is 500
Good results were obtained with a pitch of 80 mm for a length of mm. But this is not the upper limit.

It is sufficient that the pressure of the straightening roll has a load capable of flattening the softened laminate. For example, 500mm x 300mm
For a glass epoxy resin plate with a size of x 1.6 mmt, a line load of at most 10og was sufficient.

The conveyance speed is determined by the heating and cooling means and conditions, and it is sufficient if the heating and cooling conditions are set. However, cooling hardening requires horizontal maintenance until complete hardening is achieved, at which the glass transition of the constituent molecules is stochastically zero. In this sense, rapid cooling reduces the burden on equipment. Cooling means include air cooling and water cooling, and the cooling rate is adjusted by air temperature and air volume in the case of air cooling, and by water temperature and water volume in the case of water cooling.

[Example] Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, the series of steps is divided into a heating zone and a cooling zone, and the heating zone is provided with a plurality of conveyor rolls 2 placed in opposition at regular intervals in a heating furnace 1, and heaters 3 are provided above and below the conveyor rolls 2. ing. The cooling zone is provided with a plurality of straightening rolls 4 that pinch the laminate at regular intervals. If it is a water-cooled type, spray water, etc. in the cooling zone.

A-1 is a laminated plate of treated materials A-1, A-2, and A-3.
A-2 shows a material whose main material is in a softened state, and A-3 shows a material which is being straightened and cooled while being transported.

Using such a device, warp and twist 500mm (length) x 333mm (width) with a twist size of 10mm or more.
Paper/phenol substrate (A
) and glass/epoxy substrate (B), two types of unclad laminates were corrected.

For comparison, as shown in FIG. 2, three rolls 5.
6.7 is arranged as shown in the figure, and a guide roll 8.9 is used between the rolls 6 and 7 to wind the belt 1o@, a part of which is brought into close contact with the lower surface of the roll 5. Correction was performed using a testing machine. The difference between the upper surface of the roll 6.7 and the lower surface of the roll 5 was the amount of reduction, and the amount of reduction was 80 mm.

From the substrate input direction 11 of this reverse deflection tester, between the roll 5 and the belt 10, the substrate A used in the above example,
The same board as B was used and the reverse deflection was corrected.

The test results of the above examples and comparative examples are shown in the table.

As is clear from the table above, 1. In the case of the example, the percentage of warpage and twisting of 5 mm or less was 100% for both A and B.
Moreover, the warpage rate and twist rate were 1% or less. The effect was remarkable compared to the comparative example.

[Effects of the Invention] According to the present invention, it is possible to continuously and accurately correct a warped, twisted, etc. laminate.

Even copper foil or adhesive-coated laminates can be corrected without any trouble.

Therefore, highly accurate products can be obtained by using it for printed wiring boards, insulating boards, etc.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example of an apparatus suitable for implementing the present invention, and FIG. 2 is an explanatory diagram of a reverse deflection tester. DESCRIPTION OF SYMBOLS 1... Heating furnace, 2... Conveyance roll, 3... Heater, 4... Straightening roll, 5, 6.7... Roll, 8
．． 9...Guide roll, 10...Belt, 11...
- Board loading direction.

Claims (1)

[Claims] A method for straightening a laminate, which comprises heating the laminate to a temperature higher than that at which the main material of the laminate softens, and passing it between straightening rolls to correct deformation while cooling and hardening.